Two of Britain's biggest trade unions yesterday launched a campaign urging people not to buy Peugeot cars.

The Transport and General Workers Union and Amicus will place a series of adverts in national, regional and trade newspapers and display posters on hoardings across the country encouraging consumers to boycott Peugeot and Citroen cars.

The unions said they wanted Peugeot-Citroen to consider a survival plan for Ryton they had drawn up to avoid being "penalised" by the British public. Officials also urged millions of trade union members not to buy Peugeot or Citroen cars and warned they could adopt similar tactics against other companies which moved production away from the UK.

TGWU general secretary Tony Woodley said: "The unions have produced a robust plan which could provide a profitable future for the Ryton plant. Peugeot is motivated by sheer greed and needs to understand that there will be painful consequences if they shut up shop in Britain in this fashion. If they refuse to talk, and our members who will still be working at the plant after forthcoming redundancies want our support, we will fund a campaign to make the public aware of this corporate betrayal."

Derek Simpson, general secretary of Amicus, said: "Companies that seek to sell in Britain should build in Britain. We believe that the wider British public will want to send a powerful message to companies like Peugeot that are prepared to close profitable and productive plants in the UK and lay off loyal, skilled and hardworking employees. A drop in sales will really hit them where it hurts.

"We need to draw a line in the sand and say to companies that behave in this way that there will be consequences for their actions."

Workers at the Ryton factory voted earlier this week not to take industrial action to try to persuade Peugeot to reverse its decision.

Despite the vote, union leaders said they would continue with their campaign to save it as well as pressing the Government to strengthen labour laws to give more protection to workers.

The unions submitted a plan last month to the company which involved moving Ryton to a single shift operation from July and said they could significantly cut costs by reducing labour costs and management overheads.

Unions said they strongly believed manufacturing companies should build products where they sold them. Peugeot Citroen sold more than 280,000 vehicles in the UK last year, achieving more than ten per cent of the market share.

The UK is the company's third biggest market worldwide behind France and Spain. The unions said they had accepted the need to eliminate a shift at Ryton with the loss of more than 1,000 jobs in the short term and claimed the firm had turned down their offer without any discussion.